Image data (including video data and still image data) can have any one of a wide variety of different formats. Some example image data formats are: RGB, YLU, GIF, TIFF, JPEG/JIF, PNG, BMP, PDF, RAW, FITS, MPEG, MP4, high dynamic range (HDR) formats such as BEF, HDRi, JPEG XR, JPEG HDR, RGBE, ScRGB and many others. Image data formats can have capabilities that differ significantly in areas such as, for example, the range of different colors (i.e. gamut) that can be specified, the range of luminance levels (i.e. dynamic range) that can be specified, the number of discrete colors within the gamut that can be specified, the number of discrete luminance levels that can be specified, and the like. Some image data formats have multiple versions having different capabilities.
Colors may be specified in many different color spaces. Some examples include RGB, HSV, CIE LUV, YCbCr, YIQ, xvYCC, HSL, XYZ, CMYK, CIE LAB, IPT, and others. Different image data formats may specify colors in different color spaces.
Displays may incorporate any of a wide variety of underlying display technologies. Display technologies range from digital cinema displays to television sets which may comprise: liquid crystal display (LCD) panel displays in which the LCD panel is backlit by various types of backlight systems; light-emitting diode (LED) displays; organic LED displays (OLED displays); plasma displays; cathode ray tube (CRT) displays; laser projectors; digital mirror device (DMD) displays; electroluminescent displays; and the like. Within any of these general technologies a wide variety of different constructions and compositions for light-emitting and/or filtering elements are possible. As a result, different displays may have capabilities that differ significantly in areas such as, for example, the range of different colors (i.e. gamut) that can be displayed, the range in luminance values that can be displayed (i.e. the dynamic range of the display), and the like.
A wide gamut display may be capable of reproducing colors which are outside of the gamut that can be displayed on conventional displays. However, the range and number of discrete colors that can be specified by the image data provided to a display may be constrained by several factors, such as, for example, capabilities of the image data format, image data bandwidth, image data compression, and the like.
There is a need for methods and apparatus for processing and displaying image data with different gamuts. There is a need for methods and apparatus for processing and displaying image data so as to reproduce on a display different colors with a high degree of precision. There is a particular desire for methods and apparatus that can convey image data in an efficient manner to a display or other downstream device, and that can operate within the constraints of different image data formats, available image data bandwidth, and image data compression.